Photochemical image generation in a cyanogel system synthesized from tetrachloropalladate(II) and the trimetallic mixed-valence complex [(NC)(5)Fe(II)-CN-Pt(IV)(NH(3))(4)-NC-Fe(II)(CN)(5)](4-): consideration of photochemical and dark mechanistic pathways of Prussian blue formation.

The cyanogel system involving PdCl(4)(2-) and the mixed-valence complex [(NC)(5)Fe(II)-CN-Pt(IV)(NH(3))(4)-NC-Fe(II)(CN)(5)](4-) is reported. The system has been characterized by UV-vis absorption, diffuse reflectance infrared, and resonance Raman spectroscopies. Gelation occurs through coordination of Pd(II) to the nitrogen atom of terminal cyanide ligands in the mixed-valence complex.